Mercedes Blue Zero

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Mercedes Blue Zero

Mercedes believes it has found a way to make alternative fuel cars more affordable and therefore more acceptable.

At the Detroit motor show it wheeled out an all-electric concept car - the first of three different alternate-fuel models that will appear under the Blue Zero banner.

By sharing many of their most expensive components - the 'sandwich floor' architecture of the A- and B-Class, lithium-ion battery packs housed within the floor and front axle-mounted electric motors to drive the front wheels - they can be made more affordably.

The biggest difference between them is how they create the electricity to power themselves.

The cars
The fully-working car driven into a presentation on the eve of the show is a plug-in electric model capable of up to 125 miles between charge-ups. Mercedes plans limited on-road tests of something similar next year.

It is also working on a version with a hydrogen fuel cell to create electricity. This would be able to go twice as far as the plug-in model before it needed topping up with hydrogen. Road trials with up to 1000 cars are due to start later this year.

The third option is to have a plug-in electric car that can do around 60 miles between charges, linked to the 1.0-litre petrol engine from a Smart. The petrol engine would act as a generator for the batteries to allow it to go longer distances. Mercedes says that would give the car a range of more than 350 miles.

Answering the critics
Dr Thomas Weber, the company's head of research and development, says the range that alternate-fuel vehicles can cover has long been a major issue, but that Mercedes is now delivering 'convincing answers'.

'Affordability is also a key task for engineers,' he said. 'Cars like these are not possible in small volumes. The solutions will come from modularity such as we are showing here.'

He also said Mercedes is 'open' to working with other companies to reduce development and production costs.

On the future of fuel cells, Dr Weber said: 'We as car manufacturers are ready. What we now need is an infrastructure (refuelling stations).'